Baby pics + an ID question

My six baby chicks came from ideal about a week ago. They are adorable and my wife is completely smitten (some might say obsessed!). We ordered two RIRs, two Buff Orpingtons, and two Ameraucanas/EEs.

five of the six chicks are relatively self-explanatory, but one of the EEs looks far different from the other one (a dark brown without the chipmunk stripes). I think she ( or perhaps he, but hopefully not) might be a different breed. If anyone can help me out, that would be great. Anyway enjoy the pics!